Tucson Lifestyle February 2017 : Page 58

As we age, our immunity to disease declines. We talked to local experts to see what can be done to extend our healthspans. By: Britt any SemBar-myerS | Photogr aPhy By JameS P a trick IMMUNE STRUCK In Health any Americans seek a lon-ger life, and every year more of us surpass 100 years. However, lifespan is only half the picture; healthspan should be of equal or paramount impor-tance. “We have managed to extend lifespan quite a bit, but the health-span, as we call it, is really the quality of life. It’s what every-body wants,” explains Janko Nikolich-Žugich, M.D., Ph.D., who is the Co-Director of the UA Center on Aging, Elizabeth Bowman Professor and Head of the Department of Immunobiology, University of Arizona College of Medicine, a member of the UA BIO5 Institute, and Chairman of the Board & CEO of the American Aging Association. “Nobody wants to live another twenty years and be miserable with several chronic diseases.” M he guiding light of healthspan is our immune system. It’s our protection from the environment. Within the immune system are white blood cells, which protect the body from foreign pathogens. One type of white blood cell is the T cell, learning and recalling strategies of defense throughout our life. For this to work efficiently we must elicit the assistance T Fits To A “T” of naïve T cells. “We call the cells naïve T cells because they have never seen their microbe before,” says Dr. Nikolich-Žugich. “The way that this works is that we’ve got a huge army of these cells that is very, very diverse and capable of recognizing just about any microbe that’s going to attack us. In our youth we don’t have a prob-lem because our army is chock full of new recruits that are there to fight off these new infections but starting after puberty there begins an almost ten-fold drop in the abil-ity to make these cells.” After successful remediation of a foreign invader, some naïve T cells rewire themselves to become memory T cells. When the immune system encounters the same or very similar pathogens, the memory T cells can recall the effective strategies and quickly mount a defense. As we age the production of naïve T cells continues to drop. Consequently, protection from new infections and the response to known infections decreases. “Those that are the most danger-ous are the ones that people have not experienced in their life. Older people have a very hard time dealing with a completely new virus or bacteria that has been introduced into the popula-tion,” states Dr. Nikolich-Žugich. Although memory T cells sur-vive almost indefinitely, naïve T cells are necessary to continue 58 TUCSON LIFESTYLE | FEBRUARY 2017 TucsonLifestyle.com